textproduct: Albany

WHAT HAS CHANGED

Only minor changes made to the previous forecast.

KEY MESSAGES

1) Tranquil and pleasant weather is expected today.

2) A period of beneficial, widespread rain is expected Sunday into early Monday. No flooding is anticipated.

3) A cold front will move across the region with some showers on Tuesday, followed by a cooler and dry air mass mid to late next week.

DISCUSSION

KEY MESSAGE 1...As of 2:30 MA EDT...Current sfc analysis shows a broad 1026 mb sfc high building over the region from the W/SW, although some thin, high clouds associated with TC Isaias are streaming over southern areas, while a few lake effect clouds have been across the Capital District, Mohawk Valley, and southwestern ADKs earlier tonight with the lake moisture becoming trapped beneath a sharp low/mid-level inversion seen on the 00z KALY sounding. Lowering inversion heights and weakening winds should keep additional lake effect clouds closer to the lakeshore through the rest of the night, so even the areas that are running a little warmer than previously expected should still seep temps drop several more degrees between now and sunrise. Lows will generally be in the 30s to low 40s, with some upper 20s possible in the ADKs. Some patchy river valley fog will be possible, as well as some frost where temps drop near or below freezing tonight. However, for areas where the growing season is still ongoing, frost is expected to be too patchy to warrant frost advisory issuance.

Large-scale subsidence is expected today as the sfc high remains overhead and strengthens beneath confluent upper flow on the poleward side of an amplifying upper ridge. After a cool start to the day, highs rise into the 50s to low 60s with calm winds and low humidity. Tonight, the sfc high will be close enough for temps to drop quite quickly after sunset, but temps should level off or even rise slightly towards sunrise as high clouds increase in coverage. NBM seems to have caught onto the radiative cooling trend, so only minor downward adjustments were needed with this forecast package. Lows again range from the 30s to low 40s, with the coolest temps across northeastern areas tonight.

KEY MESSAGE 2...Isaias has mad landfall along the Gulf Coast as a hurricane this evening. Its remnants are expected to track northwards into the region tomorrow. PWATs rise to around 1.3 - 1.5" tomorrow into tomorrow night. The best low-level warm advection remains just south of our region, which is where the highest rainfall totals of around or just over an inch are expected. Some enhancement from the left exit region of an upper jet streak is expected here as well. However, a band of mid- level FGEN across the region and the right entrance of the upper jet to our north will allow the precip shield to overspread our entire CWA, with a quarter to half inch for our northernmost zones, with a half to 1" of rain for the rest of our area. Even if some locally higher amounts occur like the NAM suggests, flooding is still not expected given dry antecedent conditions and significantly weakened state of the sfc low as it tracks south of Long Island. This will be a very beneficial rain for the region.

There is still some uncertainty in just how quickly rain overspreads the region tomorrow, but southern areas should begin to see rain develop by mid-morning, with rain reaching the I-90 corridor by mid- afternoon and finally our northeastern zones by sunset. Rain tapers off to showers Sunday night, with showers generally ending by 12z Monday. Monday now looks mainly dry, with a narrow ridge of high pressure building over the area. Temps likely end up a few degrees above normal, mainly in the mid and upper 60s.

KEY MESSAGE 3...Tuesday into Tuesday night, a cold front looks to move through the region, bringing another chance for showers. We may briefly get into a warm sector Monday night into early Tuesday, but a wave of low pressure is expected to develop along the frontal boundary to our north, helping push it southeastwards from southern Canada through our region Tuesday. There remains some uncertainty in how close to our region the developing sfc low will track, but if it tracks to our north (which is the current consensus), then there could be enough instability for a few rumbles of thunder with the showers ahead of the frontal passage. We dry out Wednesday and Thursday with sfc high pressure building overhead again. However, the pattern aloft does not look quite as amplified as it did a day or two ago. So, while it will cool down with temps a few degrees below normal, this cold shot does not look as impressive as noted in previous forecasts. Looking towards the end of the forecast period, we may begin to warm up towards the very end of the week ahead of another storm system expected to track to our west next weekend.

AVIATION /10Z SATURDAY THROUGH WEDNESDAY/

Through 12z Sunday...There remains a low chance for some patchy fog at GFL over the next couple hours, but otherwise all terminals will see prevailing VFR conditions with just FEW to SCT high clouds around today into tonight. High clouds thicken overnight tonight from south to north. ALB/POU/PSF remain VFR through the entire TAF period, but patchy fog may develop again tonight at GFL if there are enough breaks in the high clouds. Winds will generally be light at 5 kt or less at all terminals through the entire TAF period.

Outlook...

Sunday Night: High Operational Impact. Definite SHRA...RA. Columbus Day: No Operational Impact. NO SIG WX. Monday Night: Low Operational Impact. Slight Chance of SHRA. Tuesday: High Operational Impact. Definite SHRA...TSRA. Tuesday Night: High Operational Impact. Likely SHRA. Wednesday: Low Operational Impact. Slight Chance of SHRA. Wednesday Night: Low Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.